A review: Antimicrobial activity and toxicity analysis of the peel of banana, pomegranate, papaya, and citrus fruits (lemon and orange)

Abstract

Fruits have nutrients and health-promoting compounds and usually fruits are eaten fresh with minimally processed. To meet rising demand, the production and processing of horticultural crops of fruits have grown massively in response to the population and changing dietary habits. It is rarely known that some fruit wastes, including peel, actually have their own advantages to humans as well as industry. In fact, these fruit wastes, including fruit peel, should be handled and used to minimise the environmental impacts. The functional properties of the peel of banana, pomegranate, papaya, and citrus fruits such as lemon and orange can beneficially help in the production of new health products and in food industries. Antimicrobial compounds in fruit peel play an important role in inhibiting the microbial growth, specifically pathogenic microorganisms such as Escherichia coli, Bacillus aureus, Campylobacter, Salmonella, and Staphylococcus aureus. The antimicrobial compounds present in the fruit peel are typically secondary metabolites consisting, in particular, of phenolic compounds, steroids and alkaloids, which give certain functional effects on human health. It has been reported that every fruit peel has its own antimicrobial compounds which are responsible for inhibiting microbial growth. These fruit peel, despite their beneficial effects, have also been shown to have toxicity effects on their consumption depending on the amount of doses used in the implementation. This review covers physiological properties, chemical properties, antimicrobial activity, and the toxicity analysis of the fruit peels from banana, pomegranate, papaya, and citrus fruits.